Transmission synchronizer



Off

P. ORR

` ay 24, 193s.

TRANSMISSION SYNCHRONIZER Filed July 2o, 1936 Patented May 24, 193s 2,118,619

UNITED STATES- PATENT OFFICE 2,118,619 'rmsimsslon sYNcnaomzEa Palmer Orr, Muncie, Ind., assignor to Borg-WarllirnCigrporation, Chicago, Ill., a corporation of Application July 20, 1936, Serial No. 91,457

3 Claims. (Cl. lim- 53) This invention relates to transmission synpower, there is shown a portion of a frame I in chrpnizers. The invention is concerned more which a drive shaft 2 is journaled at 3, a counterparticularly with synchronization of driving and shaft l and a gear 5 receiving torque from the driven transmission elements immediately prior drive shaft 2 through gears on the drive shaft 5 to establishing positive drive therebetween in such and countershaft, the gear 5 being journaled on 5 manner that clashing of the interengaging posia bushing 6 about a driven shaft 'I journaled at tive drive clutch elements may be substantially 8 in the drive shaft 2. Splined at 9 to the driven avoided and their engagement may be effected shaft 'I intermediate the drive shaft 2 and the with despatch.' gear 5 is a clutch ring IU arranged to have slight 10 It is an object of the invention to provide a longitudinal floating movement relative to the 10 synchronizing mechanism of such character as to driven shaft 1. Slidably splined on the outer peprevent clashing of coupling parts under normal riphery of the ring I0 at Il is a clutch collar I2 driving conditions. whose teeth I3 are adapted to be clutched with It is also an object of the invention to provide clutch teeth I4 on, the drive shaft 2 to establish a synchronizing structure which will insure a driving connection between the drive shaft 2 15 against coupling action or engagement of clutch and the driven shaft I through the clutch ring teeth prior to substantially complete synchronizal0, and with clutch teeth I5 carried by the gear tion of the parts to be coupled together. 5 to establish a. reduced speed driving connection, A further object of the invention involves the through the ring I0, between the gear 5 and the provision of mechanism for speedily synchronizdriven shaft 1. 20 ing relatively moving parts. Suitably mounted on the frame or casing I is a In accordance with the general features of the shift rail I6 of any suitable construction, adapted invention, there is provided a blocking element to be held yieldably in the desired positions of which assumes a position obstructing the coupling adjustment by the spring pressed plunger I1 enaction upon approach of the relatively moving gaging in appropriately positioned recesses in the 25 parts to be coupled under normal driving condirail, or by any other suitable means. The shift tions, and ceases to so obstruct only when the rail I6 carriesafork I 8 received in an appropriate parts are in substantial synchronism. groove 18a in the clutch collar I2 for shifting the Other objects and advantages oi the invention same. zo will appear as the description proceeds. In synchronizing clutch structures of this gen- The invention will be best understood by referal character heretofore in vogue, suitable griperence to the following description of the several ping surfaces have been provided on the parts embodiments thereof, shown in the accompanysuch as the parts I 0 and 5, and relative sliding ing drawing, wherein: movement of the clutch collar I2 and ring Iii has Fig. lisalongitudinal fragmentary view, partly been yieldably restrained by means such as a 35 in section and partly in elevation, of a transmisspring pressed ball I9 normally projecting into a sion mechanism embodying the invention; groove 20 in one or more of the teeth I3, until Fig. 2 is a fragmentary view, partly in section the gripping 'surfaces have established some deand partly in elevation, taken substantially as ingree of synchronization.

40 dicated by the line 2--2 in Fig. 1; In practice, however, it has been found that a@ Fig. 3 is a fragmentary plan view taken subeven under normal conditions of driving the stantially as indicated by the line 3-3 in Fig. 1; shifting force overcomes the restraint due to the Fig. 4 is a fragmentary longitudinal view, partspring before substantially complete synchronism ly in section and partly in elevation, of another and the clutch collar forges on and `clashes with form of the invention; the part with which it is intended to be coupled. 45

Fig. 5 is a fragmentary plan view, partly in sec- In accordance with the present invention, these tion and partly in elevation, taken substantially and other undesirable characteristics attendant on the line 5--5 of Fig. 4; and upon the use of conventional synchronizing mechy Fig. 6 is a fragmentary view similar to a part of anisms have been obviated. To this end, in ac- Fig. 4 but showing another form of the invention. cordance with the form of the invention shown 50 Referring now more particularly to the drawin Figs. 1, 2 and 3, a blocking ring 2l is secured ing, in which is illustrated a portion of a transat one or each side of the clutch ring I0. The mission such as may be found in automotive veblocker 2| is journaled at `22 in the ring lll and hicles, in conjunction with marine engines, and is provided with one or more slots 23 so dimenin fact in any assembly for the transmission of sioned as to permit relative rotation between 55 the parts III and 2|. The'retractor means serves to return the blocker axially with the ring III when the latter is returned to neutral position, to prevent accidental drag of the blocker against the cooperating friction surface when the transmission is out of second gear. o

Three sets of slots and retractors preferably equally spaced angularly may be employed. The blocker member 2I is provided with one or .more outwardly projecting lugs 25 projecting generally radially through adjacent, substantially registered notches 25 and 2l in the ring I5 and collar I2, respectively. 'nie end portions of one or more teeth on the outer periphery of the ring and inner part of the collar are accordingly removed to provide these notches. The notches are wider than the lug 25 to aord limited relative rotation between the blocker 2I and the ring I0. The sidewalls of the -notches 21 are tapered at 25, as are also the confronting sides 25 of the lug 25. so that when the lug 25 is in other than its median position (shown in full lines) relative to the ring Ill, the lug obstructs one or more of the chamfered adjacent teeth Il of the collar I2, and while in the obstructing position prevents the collar I2 from moving relative to the ring Il in the direction of the lug 25.

The collar I2 is provided with a longitudinal internal groove 30 formed by removing one or more teeth Il and preferably a few thousandths of an inch wider than the lug 25 to provide clearance for each lug, and is adapted to receive the same when the blocker 2I is in its median position aforesaid, which occurs upon substantial synchronization between the shaft I and the gear 5 as will appear hereinafter. Thereupon said collar may be shifted longitudinally and coupled with the clutch teeth I5 on the gear 5.

A friction ring 2i, of bronze or bronze composition or any other suitable wear resistant friction material. is riveted or otherwise suitably secured to the blocker 2I and has a preferably frusto-conical friction surface 52 engageable with a complemental frusto-conical surface 33 formed on the gear 5 or on a member secured thereto. Ihe juxtaposed ends of the cooperating teeth Il and I5 are suitably chamfered or rounded to provide such camming as is necessary to enable the teeth to be clutched together notwithstanding any disalignment as the teeth are initially enmed- By way of example, let us consider the driven shaft I to be the transmission main shaft illustrated in S. 0. White U. B. Patent No. 1,872,566, issued August 16, 1932, the shaft 2 as the drive shaft, the gear 2a thereon as the drive gear and the gear 5 as the second speed gear, constantly rotated by the drive shaft 2. Let us assume a condition wherein the parts are arranged substantially as shown in Figs. 1, 2 and 3, with the transmission in low gear or in any other condition with the transmission main shaft l rotating at a lower speed than the secondspeed gear 5. l'lor the purpose of shifting into second speed, the low speed drive is released and pressure is applied to the fork Il in the direction to shift the coupling collar I2 to the right as seen in Fig. l. Since the ring I5 is oatingly slidable along the transmission main shaft l, the unit comprising said ring, the blocker 2 I, friction cone 5Iandcollar|2wi1lbemovedbodilytothe right until the axial clearance between the friction surfaces I2 and 5I is taken up. The obstruction afiorded by the friction surface 32. while preventing further sliding of the ring I5,

aiiaeic would not prevent continued movement of the collar I2, movement of the latter being merely yieldably resisted by the spring pressed ball I9 in the groove 25. However, due to the frictional engagement at the surfaces 52 and 2l, and the fact that the gear 5 and shaft 'l are moving at different speeds (the gear 5 moving faster than the shaft I but gradually reducing its speed due to the drivers release of the accelerator upon shift from low to neutral, preparatory to the shift to second speed, while the shaft 'I coasts or free wheels at substantially the same speed at which it was rotating in low), the surface 33 will apply a torque upon the blockerv ZI and turn it relative to the ring I Il substantially to the position shown in dotted lines at 25a in Figs. 2 and 3, with one wall 29 of the lug in engagement with the adjacent wall 25 of the notch 21 in the coupling collar I2. f

As long as the gear 5 rotates faster than the shaft 1,

the torque applied to the friction ring 3 I will maintain the lug 25 in the position 25a, where, as has been explained, the lug obstructs the juxtaposed ends of the teeth I2 of the collar I2 and thus substantially prevents movement of the collar I2 toward teeth I5 on the gear 5. During normal conditions of driving, the greater the force applied to the collar I2 tending to effect a coupling thereof with the teeth I5, the greater will be the obstructive force exerted by the lug 25. and the greater will be the grip between the surfaces 32 and 3l, and consequently the quicker the synchronization of said surfaces will occur. f course, inasmuch as the engine clutch is released, the gear rapidly slows down, thereby additionally hastening synchronization.

It will be appreciated that, once synchronization has been reached, the gear 5 tends to slow down further because of friction, so that immediately following the instant of synchronization, the surface 23 exerts upon the blocker a torque which is opposite in direction to the torque previously applied thereto, with the result that the blocker is now shifted relative to the ring Ill toward the position shown in full lines, with each lug in registration with the longitudinal groove Il in the clutch collar I2. During this shift of the blocker, pressure is continuously applied from the collar I2 against the lug 25, so that as soon as this shift commences, the groove III receives the reduced part of the ,lug, and as such shift is continued, the lug recedes further rotatlvely from the notch wall 25 appearing lowermost in Fig. 3, and therefore permits further approach of the collar I2 toward the teeth I5, the groove 35 receiving more and more of the lug.

As soon as complete registration of the groove and lug occurs, the lug ceases to obstruct any of the teeth of the collar I2 so that the latter is free to move without interference in the direction of the teeth I5 and to interlock therewith, thereby positively coupling together the ring I5 and gear 5. and establishing second speed drive. When the collar I2 has reached the coupling position, shown dotted in Fig. 1, pressure thereon is released, and thereafter the ring 2i is contrclled longitudinally relative to the collar I2 by the friction due to pressure of the ball I5 on the straight edge portion 25a of the associated collar tooth Il.

The amount of movement of the collar I2 to effect its proper engagement with the teeth I5 is such that when clutch engagement occurs the plunger Il is still in engagement with a tooth 0I the collar I2.

When the parts are in therelation shown in Fig. 1, with the lug 25 in its median or neut'ral position offering no obstruction to the movement of the collar l2, the spring pressed plunger i9 in the recess prevents the collar I2 from accidentally moving longitudinally relative to the ring I0. When the collar l2 is initially moved toward the teeth l5, pressure is transmitted by a wall portion of the recess 20, engaging the ball I9, to the friction surface 32, causing the latter to be engaged with the surface 33 to commence the synchronizing operation. It is only after perfect synchronism is effected that the lug is fully registered with the groove and, at such time, the continued shifting pressure upon the collar I2 overcomes the pressure of the spring pressed ball I9 and forces the latter out of the recess 20.

Consideration has been given to the mode of operation of the invention insofar as the shift from a lower speed to second is concerned. Following release of the coupling between the high speed coupling teeth l4 and the collar I2, in the shift from high to second, it will be evident that due to the fact that the main shaft 1 will be proceeding under the momentum of the vehicle at a higher speed than the engine will be driving the second speed gear 5, the torque by the gear surface 33 upon the blocker ring surface 32 will be in a direction opposite to that exerted when changing from low to second, so that, relative to the ring I0, the lug 25 will occupy a position indicated by the dotted lines at 25h in Figs. 2 and 3. As before, the lug in this position will prevent the collar-l2 from moving into engagement with the teeth l5 until after synchronism has been reached and momentarily passed, the gear 5 being then rotated momentarily faster than the shaft 1 until the lug no longer obstructs the collar and the latter is thereupon free to shift longitudinally into engagement-with the teeth l5.

While the blocker mechanism is illustrated in Fig. 1 as applied only to the second speed side of the ring l0, the high speed synchronizer cone surfaces being without such mechanism, it is to be appreciated that it could well be provided on the high speed side or on both sides of the ring I0.

The blocker 2l has a slight vaxial clearance as shown in Fig. l to insure relative rotation, yet is retained by the screws 24 against accidental drag against the surface 33 when the transmission is out of second gear.

In Figs. 4, 5 and 6, modified forms of the invention, affording blocker mechanism for both second and high speeds, are illustrated. Accordingly it will be appreciated that the collar 35 is provided with a longitudinal inner opening 35a and is formed at both ends with generally radial notches 36 corresponding with the notches 21 of the form of the invention previously described. 'I'he clutch ring 31 is similarly notched for registration with the notches 36 and for receiving the lugs 38 and 38 of blocker rings 39 capable, because of the greater width of the notches, of limited rotary movement relative to the clutch ring 31. The blockers 39 have sliding rotation in the ring 31 and bear upon the ring 31 along frusto-conical surfaces 40 and outwardly disposed substantially cylindrical surfaces 4I. The engaging surfaces between the blockers 33 and the ring 31 and collar 35 are preferably so formed as, and sufficient clearance is provided, to obviate any tendency to stick. The blockers are rotatively floatingly supported by the ring 31. They may be capable of slight axial movement with the ring 31, limited'by the proximity of the axially` relatively xed frusto-conical surfaces 42 of the transmission drive shaft 43 and the second speed gear 44, respectively. The gear 44 may be journaled on the transmission main shaft 45, and the bushing 46 may be suitable for this purpose. The blocker rings 39 are preferably provided with bronze or other suitable friction insert rings 41 riveted or otherwise suitably secured in place and having friction surfaces 48 complemental with the surfaces 42 and cooperative therewith to Cif-Tet synchronization in substantially the same way in which the surface 32 cooperates with the surface 33 in Fig. 1.

From the explanation already given in connection with Fig. 1, it will be appreciated that, in connection with the forms shown in Figs 4, 5 and 6, when the shift is commenced from low to second, the lug 38 initially will be shifted, relative to the ring 31 and collar 35, to the position shown in dotted lines at 38a in Fig. 5 before reversing and being received in the groove 35a, and when the shift is from high to second, the lug 38 initially will be shifted, relative to said ring and collar, to the position shown in dotted lines at 38D before reversing and being received in the groove 35a. It also follows from said previous explanation that when the shift is to high from a lower speed, the left lug 38 will be shifted initially, relative to said ring and collar, to the position shown inldotted lines at 38C before reversing and being received inthe groove 35a. In

the establishment of second speed, the internal` teeth 48 oi the collar 35 will engage the teeth, 511

associated with the second speed gearv 44,;and in the establishment of high speed, the internal teeth 49 will engage the teeth 5| associated. with'` the drive shaft 43.

Although the walls of the notches 26 in the rst described form of the invention are substantially fiat throughout, they may be made angular as shown in Figs. 4, 5 and 6, in complement tothe correspondingly formed and juxtaposed walls of the lugs 38 and 3B. These lugs, moreover, preferably project into the groove 35a to assist in telescoping the lugs fully into the groove as the occasion may require.

In order to prevent rattling or any undesired drag between the surfaces 42 and 48, a retractor clip 52 for substantially preventing relative 1ongitudinal movement between the rings 39 and the ring 31 is provided. The clip may be of any desired construction, and for purposes of illustration is shown to comprise a strip of any suitable material such as metal. It is preferably so dimensioned as to be freely movable in the groove 35a, and permit free relative rotation of the lugs 38 and 38 and the associated parts, and has end walls 53 engaging the outer end Walls 54 of the lugs.

The clip, as will readily be observed, is applied by merely slipping the same over the lugs 38 and 38 prior to assembly with the collar 35 and after the blockers 39 are assembled with the ring31, with the end walls of the clip engaged with the outer end walls of the lugs. The lugs may project radially less than the out'er teeth of the ring 31, if desired, to enable such teeth to assist in holding the clip in place. Thereafter this assembly is slipped into the collar 35 in the relation shown in Figs. 4, 5 and 6.

Fig. 6 shows substantially the same construction as Figs. 4 and 5 but with the retractor clip 52 omitted.

and 215' It will be observed that the invention is applicable to `brakes as well as clutches.

It will be understood that the tooth coupling occurs immediately following synchronization, before any substantial speed difference occurs, so that the coupling is eifected freely and without clashing; The adjacent teeth ends are preferably chamfered or rounded to facilitate coupling of initially disalined coupling teeth.

'I'he cone rings are preferably of bronze for engagement with the preferably steel or other relatively obdurate or hard cooperating surfaces associated with the gears, due to the high coemcient of friction afforded.

The blocker lug portion of each blocker ring is preferably of steel or other suitable obdurate material resistant to bending and other stresses to which the lug is subjected in the synchronizing and coupling operations.

'I'he gearing may be of the spiral or any other suitable type if deisired.

The invention is fully applicable to automatic and part-automatic as well as hand shift power transmission or absorption mechanism.

When the shift is from high to second, coupling may be speeded up by speeding up the drive shaft 2 as soon as the lug obstructs further longitudinal movement of the clutch collar. This speeding up of the drive shaft will speed up the second speed gear and hence hasten the synchronization and subsequent reception of the lug in the collar groove, where the lug no longer obstructs the collar. Of course, even without this speeding up, the coupling will be enected with despatch.

It will be seen from the foregoing that in accordance with the invention under normal driving conditions silent shift to couple relatively rotating parts may be accomplished, and in addition the synchronization is both speeded upl and made positive prior to lnteengagement of the coupling teeth.

When the invention is employed in connection with the maximum speed drive, or as a brake, it is clear that the lug will be moved on only one side of its neutral position and hence the notches in the clutch ring and associated collar may be shaped to extend only on one side of the groove 30 or lla, as the case may be, at the high speed end associated with the drive shaft in the instant drawing, for example.

In a structure embodying this invention, synchronization is eifected so quickly that for practical purposes the entire shift of the coupling collar member is substantially continuous.

Iamawarethatmanychanges maybemade and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I therefore do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

1. In a transmission synchronizing mechanism, separable torque-transmitting parts adapted to be drivably coupled together, a synchronizing member having a rotary lost motion relation with one of said parts, and a synchronizing member substantially nxed to the other part, a coupling device slidably splined to one of said parts and having a longitudinal groove adapted to receive a portion of the nrst member as said device is moved into coupled relation to the other part, and a retractor clip extending in said groove and embracing said first part and said first member for retracting said irst member out of engagement with the second member upon retraction of said device.

2. In a transmission synchronizing mechanism. separable torque-transmitting parts adapted to be coupled together, a synchronizing member on one of said parts, a synchronizing member xed to the other of said parts, a coupling device slidably splined to one o f said parts and having a longitudinal groove adapted to receive a portion of the first member as said device is moved into coupled relation to the other part, and means extending in said groove and embracing said tlrst part and said nrst member for retracting said firstl member out of engagement with the second member upon retraction of said device.

3. In a transmission synchronizing mechanism, separable torque-transmitting parts adapted to be coupled together, a synchronizing member on one of said parts, a synchronizing member fixed to the other of said parts, a coupling device slidably splinedto one of said parts and having a longitudinal groove adapted to receive a portion 'of the nrst member as said device is moved into coupled relation to the other part, and a clip extending in said groove and having depending ends, said ends including between them said first part and said first member for retracting said first member out of engagement with the second member upon retraction of said device.

PALMER ORR. 

